A few pilots have told the Air Force they won't fly their expensive F-22 Raptor stealth jets because no cause has been found for oxygen deprivation incidents in the cockpit, the head of Air Combat Command for the U.S. Air Force told reporters.

The Air Force has been looking for the cause of about a dozen unexplained incidents related to hypoxia, or oxygen deficiency, with pilots, but so far has been unable to pinpoint it, Gen. Mike Hostage with Air Combat Command said in a media briefing.

Hostage noted it was a very small group of pilots who opposed flying the Raptors. Pilots began experiencing problems starting four years ago.

Hostage said if a contaminant is not the problem, there may be something else hindering pilots from getting enough oxygen.

Hostage spoke at length with reporters about the issue, which has plagued the fleet since problems with the F-22’s oxygen supply system were first reported in 2008. The jets have previously been grounded to examine the issue , but one year ago the Raptors were again cleared and allowed to fly. In January 2011, the jets were limited to altitudes under 25,000 feet during an ongoing investigation into a November 2010 crash. Flying above that altitude could cause a pilot to black out from lack of oxygen and lose control.

"We are diligently pursuing a variety of hypotheses to try and understand and characterize the exact circumstances we've been experiencing," he said.

The Air Combat Command said it still has not identified the "root cause" of the oxygen issue, but is making progress with its investigation and hopes to soon determine the exact cause of the problem.

“The smoking gun is disassembled in a mosaic in front of us. ... At some point we’re going to have the smoking gun assembled,” Maj. Gen. Charles Lyon, the director of operations for ACC, told the Air Force Times.

While Hostage said that there was certainly a concern about the group of incidents, he didn't think it was necessary to pull the entire group of jets, which have had 12,000 deployments and a total of 15,000 flight hours since September 11 and only a handful of problems. The Air Force has also made sure to add new emergency oxygen deployment handles, should a pilot encounter any issues.

And the F-22s are still being used when needed, including a recent deployment by the Air Force of a squadron of the Raptors to southwest Asia.

"I fully expect we'll get to a solution," Hostage said. "I won't give you a timetable, but we have made great progress to that effect and am confident we'll put this behind, we'll be able to explain it, and we'll retool the airplane to make this problem go away."

You won't successfully penetrate Chinese or Russian, or simillarly defended, airspace with non low observable aircraft like the F-15. You do not understand the threat. We have rolled over a handful of second rate powers in the last two decades with F-14s, 15s, 16, and 18,s. Don't imagine for a second any of these would survive against modern air defense systems such as those the Chinese and Russians have.

Do you realize that both the Chinese and Russians are already working on fighter designs to counter the F-22? Control of the sky over the battlefield is crucial to winning any military engagement. Why would you want to depend on technology that is over 50 years old when our enemies have aircraft today that are superior to the F-15 (Mig 35 / 39, Su35)?

The P51 is an exceptional aircraft and would work great in Afghanistan or against Iran if push comes to shove over there.Its fast and can out perform most SAMs and has the capacity to carry out great close support in combat.

The next war will be fought with naval and air power in the Western Pacific and South China Sea. The F-22 and F-35 are the only two aircraft in the west that will survive against the sorts of radars and missiles we will fight against. In the last six or seven years the Chinese military has undergone a transformation that seems to have escaped the US public. Low observable aircraft are the only type that will have an acceptable survival rate fighting the Chinese if it ever comes to that, and it may.

at $150 million each and our Air Farce ordering $65 billion worth of the failed raptor-one can only wonder whats more important for America? A jet pilots are afraid to fly because its obviously defective or putting that $65 billion to better use-like extending care for the homeless,the elderly,the poor,putting money into food for the food banks or medical care for children..we waste so many billions on crappy defense equipment that does not work-but cut off benefits for those who are unemployed or cant afford to even buy food!
With so many unemployed nationwide-I think we ought to cancel this contract-divert that money into helping Americans out as a priority-use it to fund new jobs not dangerous junk with wings!

Rob2tall, the F-22 is out of production. If you remember Secretary Gates cancelled the program and production of the last funded batch of F-22's is complete. Secdef could not justify buying more examples of an aircraft that has known shortcomings where each example will need to be modified to correct problems encountered in testing and operation.

If you think our engineers failed us, then you have absolutely no idea how much we asked them to do with this airplane. it is a groundbreaking aircraft in every respect that the public has no idea how it works. If anything, the USAF was too ambitious but back when it was authorized, the Soviets were working on a pair of stealth fighters of their own. One of the two Russian designs is being tested now and we see China has the J-20 being tested. We shall see how they turn out. They seem less ambitious, and less capable than the F-22, but even still, our engineers have had over a decade to work out the kinks in exceeding Mach 2 while staying stealthy (not an easy thing to do) and launching weapons at those speeds from internal weapons bays (also a hugly difficult thing to do and remain stealthy)

Rob2tall, what do you know about modern air defense systems? An aircraft with the performance of the P-51, not to memtion it's radar and ifrared signature, would be chewed to pieces by modern air defense systems. Even our legacy fighters, the F-15, F-16 and F/A-18 will have a tough time. In Serbia, which used much older Soviet era weapons but had thoroughly modern shoulder fired missiles, our aircraft had to stay above 12,000 feet to avoid these shoulder fired missiles. We had to keep the A-10's away from Serbian forces due to the low level missile threat. The Serbs chewed up our UAV fleet pretty good. A P-51-ish aircraft would have to operate right in the thick of that threat and it would be a slaughter.

Btw, look up an airplane called the Piper Enforcer, an example of which sits at the USAF Museum at Wright Patterson AFB. It's a modern, turboprop powered iteration of the P-51. It was tested and failed to do the job. If you think a P-51 is a more capable or survivable aircraft than an A-10 then you have no credibility at all.

I understand the pilots are concerned, but they are part of the miltary and they voluntarily signed up. To be sucessful the military needs a certain level of discipline and unquestionable respect for authority. These pilots have been ordered to fly the jets, if they will not and continue to create a public display, they should be court martialed and thrown out. There is no room for this kind of disention in the military. Test pilots fly planes everyday that are not totally safe in order to collect data to help make the planes better. The airforce is basically asking the same of these pilots, in a sense re-assigning them as "test pilots" in order to collect more data in order to figure out the problem. It would not be in the Air Forces best interest to risk their top pilots unecessarily. it is about time that we wake up and realize that the peace we enjoy comes at sacrafice of our great men and women in the military and that war (and preparing for war) is not always pretty or safe. quit whinning and follow orders.

I'm a retired General Officer and fighter pilot having flown the F-15 for almost 6 years. Air to air combat engagements are probably the most demanding of endeavors that a human being faces. It is exceedingly demanding both mentally and physically. The pilot is totally engrossed in the engagement and vitally dependent upon all of his systems working to perfection for his safety and survival. The other pilots involved in the engagement are mutually dependent in both the training and combat environment. The two most threatening physiological factors a fighter pilot has to deal with are hypoxia due to lack of oxygen and loss of consciousness due to high G loading. The officers who refuse to fly an aircraft with known oxygen problems such as the F-22 with its faulty on-board oxygen generation system should be the commanders not the squadron pilots. If we were in a war-time situation that threatens our ability to accomplish our combat mission it would be one thing, but we are not at this time. The F-22 is a fabulous fighter that has time and again proved its impressive air superiority capability, but this oxygen deficiency needs to be corrected immediately before the F-22 can be considered a reliable combat effective weapon, and I believe that it will. I personally believe that it was a grave mistake to have cancelled the procurement of a much higher number of F-22s. Just the deterrent affect of its capability would have a potential adversary thinking at least twice about challenging the U.S. military.

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